


Fluffy Fell Ending

by JellyFicsnFucks



Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), Gen, Mpreg, Plot and Fluff
Language: English
Status: Completed
Published: 2019-03-09
Updated: 2019-03-09
Packaged: 2019-11-13 21:39:14
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,439
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18039542
Author URL: https://archiveofourown.org/users/JellyFicsnFucks/pseuds/JellyFicsnFucks
Summary: The swap bros are a happy couple and it makes Red and Boss jealous. They talk about what they want from a relationship.





	Fluffy Fell Ending

**Author's Note:**

> Sorry for being gone from this fandom for so long.  
> I've taken some stories with me when I left, so please excuse the mess while I re-upload old work.  
> Thanks for voting on Twitter! I will be sure to upload all the incomplete messes ahahaa  
> I'm really surprised to have a following of people who like my stuff, so thank you for the love and support. The messages I've gotten mean the world to me and it makes me terrified to let you down.  
> ฅ(๑’Δ’๑) I'm really sorry to leave you hanging for so long. Thankyou.

Red bit his inner lip, staring longingly at the playful relationship the Swap brothers had. His Papyrus nuzzled his Sans. His Sans smiled and happily booped the other's forehead…it was cute. Comfortable. And Red was entirely envious.   
   
Blue was pregnant. Again. Going for number two and the couple sat snuggly together on the sofa, ogling each other throughout the entire movie. They looked like they were really in love...  
   
Meanwhile, Boss sat on his right. A whole couch cushion and popcorn bowl widened the gap between them. Boss was engrossed in the horror movie, laughing as the main cast is slaughtered one by one. It was good to see Boss laugh again… Red felt like it had been so long since he and his brother had been this close. Recently they’d been able to talk more, been able to laugh more.  
   
Red had this feeling bubbling inside of him ever since they got the machine to work and met their swapped alternates. He thought of telling Boss that maybe… he’d like to move here?   
   
Underswap was so quiet. No monsters screaming in the middle of the night. No need to put up his guard when walking the streets alone… Monsters here were kind and honestly it was nearly identical to their own world. Same kingdom… same monsters…   
   
Would abandoning their home and making a life here be any different? He didn't want to go back home… and these short visits across universes only made him long for something more… something _homey_.   
   
His panic attacks were lessened here, warmed by the hot coco Blue would serve him and the blankets Stretch would toss his way. Boss was kinder, feeling useless while others fussed over his brother, he’d become possessive and at least try to talk about stuff. Even if it felt entirely uncomfortable to discuss timelines, resets… deaths…  Boss listened for once.   
   
Those had stopped too. The resets. Since the machine started working it seems the timeline healed itself. The human stopped coming. Boss stopped dying… now their world was back to normal.    
   
The normal “Kill or be killed” at least. It was a daily routine.  … Things were calming down a bit.   
   
So he looks over at boss, awe struck by what he was wearing today. Instead of the uptight guard uniform he never took off in company, today he had a black tanktop and jeans he’d borrowed from Stretch. He looked relaxed… right at home in Underswap. Surely he’d think it was a good idea too.   
   
The movie finishes. Blue and Stretch retire to a room to give into the lull of sleep and, as always, offer the Fell brothers the other room if they wanted to crash. Boss never does, but thanks him for the offer regardless. Thanking. That was something that was new. Sans feels emboldened. The change in Boss has happened so quickly he hopes he can make this persuasion easier.    
   
They walk out the house, into the cold snow for a moment before turning back and entering the lab behind the stairs. The chill, quickly melting in the warm room.  Boss strips himself of the casual clothes, adopting his battle armor to return home. Sans does the same, grabbing his hoodie and swapping his fluffy slippers out for the red sneakers he had worn out down to the sole.   
   
“Hey… Boss?” Sans felt anxious talking to him alone… it seemed awkward now… weird without the loud noises of their alternates creating a buffer of sound. Now it's quiet. Just them. _Just Boss_.  Papyrus turns his head, raising a brow, curious. He moves a hand to the console and punches in the address to return home. A muscle memory at this point.   
   
“What Sans?... You don’t have to wait for my approval to speak. Only around the other guard.”   
   
“Oh… right.” Sans shifts his hands into his pockets. The oversized jacket making him feel small… worthless… or maybe it was the thought of going back home that made him feel that way. Back to servant master… back to having his head stepped on, face shoved into the snow for appearance sake and being the laughing stock of monsters who’d dust him in an instant…  
   
“Sans?” Boss is snapping his fingers now, bent over Sans like a fragile doll. He snaps again trying to get his attention. Red eye lights focus on the  sharpened phalanges. “You were drifting there… nightmare again?”  
   
“... No. No! I’m awake Boss! Really awake!” He rubs the cuff of his sleeve into his right eye and tries to wipe away the tears he feels swelling up. He clears his voice, trying to sound sure of himself before asking boss something so serious. “I.. uh… I was thinking. Do… do you like… what Stretch… and Blue _have_?”  
   
Papyrus hovers over the keyboard, trying to be patient with his brothers meanderings. “Use your words, Sans. Its 3 in the morning and I don’t intend to play a guessing game with you.”   
   
“I know… _I know_.” He rubs his eyes again, feeling itchy crust in the corner of his sockets. “I like… _here_. I want to live here. Boss. … Is that okay?”  
   
There is a pause where Papyrus’s face contorts, snarls like he were addressing greater dogs and the royal pups that were hired above him at work. He glares daggers at Sans and Sans takes a step back. Unsure if Boss was about to slap him or stab him.   
   
Through grit teeth he makes a gnarled sound. “Oh---kay.” Then turns his back on Sans and fiddles with the machine address, pressing enter to confirm the command. It makes a whirring sound, toggles back and forth and flickers the lights before the machine dials shifts color from red to green to signal it was safe. “I’ll bring you your stuff tomorrow.”  He takes a step forward but Sans grabs his sleeve immediately. Halting him in his tracks.   
   
“No. Boss, I … I don’t mean I want to stay here alone.  I want you to stay here too! _We_ can live here? Right!?”  Boss turns back, the anger awash from his face. Whatever thoughts in his mind that were boiling over have melted the moment his brother grabbed his sleeve.    
   
“You don't prefer that orange sugar glutton?” Boss snarls. “He’d be a better brother.”  
   
“Of course not! I want to stay with you boss! Always! Please, I want to stay here with you.”  
   
“Why stay here though?” Boss raises a bone brow and took a step off the platform of the machine. He turned, fully humoring Red’s ridiculous idea. “Don’t you find this place dull? The people are too sweet and I’ll never get to rise through the royal guard with a bunch of nose picking idiots leading. This Undyne is a backwards sloth. And the Alphys here is ridiculously energetic and less frightening than a moldsmal. I’d prefer to go back home.”   
   
“I like the people…” Red sheepishly whispers. “I like… knowing that our neighbors won’t read our stats before they say hi. I like… watching movies really loud without worrying someone will use the noise to break in easily. I like… the fact no one is trying to kill each other.” Red mumbled. “Sure, there's no bar and that sucks, but the food at Muffets is pretty decent. And I really hate all the brats running around in the street… but there are actually brats here. There are kids and well… Stretch and Berry are having kids too...They’re settling and I- I prefer this place over home!”  
   
The machine whirs…growing hotter by the second. The bulb aboves them flickers in and out. Energy readings rising while minutes pass by unnoticed.   
   
The two bicker back and forth. Listing their likes and dislikes of this universe. For all the knots building in Sans chest he’s glad that this isn’t turning into a yelling contest. Boss was actually having a thoughtful discussion with him. Considering topic points, rebuking with his own. He was glad to hear how Boss truly felt about this world.  
   
Eventually Bos had to cut their conversation short.   
   
“Let's continue this tomorrow. I have to patrol in the morning and I could do with a few hours of sleep. “  
   
“Y...yeah sure! I’ll make you some tea.”   
   
They both step into the machine, with its warning light of yellow. It gurgles through the known universe and pops in and out with a fizzle of electricity, at last catapulting them home to Underfell. The machine sparks as it syncs into this new timestream.   
   
The two step out quickly, unsettled by the clacking of the machine. Sans rushes to the console and Papyrus grabs a fire extinguisher.  The machine warbles into itself, black smoke emanates from its exhaust pipe before the power dies, taking with it the single hanging light bulb in the basement.   
   
“What the hell was that?” Boss coughs. He stumbles in the dark, hitting his knee on a desk and curses abruptly. The pain makes him drop the heavy extinguisher too. The metal clanks and rolls somewhere unseen.   
   
“Looks like the machine overheated.” Sans pulls his sweater over his nose and mouth. Eyes watering as he peers through the computer monitor to stare at some numbers. “Overloaded some fuel cells… I think… readings aren’t good. Too much static. I’ll figure it out tomorrow.“   
   
Papyrus comes upon the door, bracing it open only for the wind to take it and smash it against the side paneling of the house. The gust of wind pours into the room, replacing the hot smoke with the chill of Snowdin.   
   
“Whatever.. Let's get inside before any asshole spots us. Lock it up.”   
   
“Got it.” Sans palms the keys and follows Boss out the room. He locks it up quickly to join him on the front porch where Boss stands next to the front door, trying his best to appear menacing despite shivering in the cold. Sans quickly unlocks the front door now and it blows open in the storm. The two frozen skeletons shamble inside and work together against the wind to seal the door back up again.   
   
Sans kicks off his shoes and slides the deadbolt over the door. “Cold. Tired. Bed.”   
   
“... Yes. Bed.” Papyrus rubs his head. Sore from too many thoughts and the small dizzy sensation he’d always got from shifting through universes. “Sans… when you said. You want what Stretch and Blue _have…_. Did you mean. … _??? well..._ ”   
   
He kicks off his shoes by the door, not bothering to straighten them. Instead he just looks at the ceiling. As if some stars had broken through the roof and caught his attention.   
   
Sans follows his gaze, looking for anything odd from a camera to a moth…  even scanning for an uneven fleck of paint. He wasn’t sure what held Boss’s scrutiny but he doesn't wonder long before he sees the flush of red on Papyrus’s cheekbones.    
   
His brother was looking away. _Shy_. Sans smirks, with a half laugh plastard on his face. He didn’t think he’d see his younger brother so embarrassed. Now he wonders what exactly is going through his mind?   
   
“...Boss? Want to say something?”  
   
He hears a small grumble. Papyrus disagreeing with his better self. “... The Swap bros… did you mean. .. you wanted to have what they _have_? That… _you know._.. sickly _sweet_ relationship?”  
   
Sans smiles. Its got to be the first time since they were kids that Boss has said something so cute and innocent. “Of course! Yes!” He exclaims out loud. “All I’ve ever wanted is to be your brother again Boss. I … I don't mind calling you Boss… and I know the collar is important to wear in public. It keeps me safe but I’d love it if we were… ya know. Close! Like they are! Laughing, joking, cooking together...  genuinely happy and-!!!”   
   
Papyrus leans in close, too close for comfort. He can smell the musk of bone off his brother and the coffee on his breath. Closing his eyes, Boss leans forward … and Sans fidgets, wanting to move his head. But he can’t do it fast enough, he and Boss clank teeth together. A skeleton kiss. The impact is harder than either intended and both begin reeling back from pain.  His fingers fly to his mouth. “!!!WHAt the hell! That hurt!”   
   
“SHUT UP! I was trying to be homosexual!”  
   
“What the hell is homosexual!? Fauk!! Damn I’m bleeding!”  
   
“I don’t know!  I’M SORRY! Undyne saw it in a manga!”  
   
“I NEed ICE!!!”   
   
“DAMMIT I SAID I’m SORRY!!”   
   
\---  
   
Twenty minutes later Sans and Papyrus are sat at the nook in their kitchen table. Sans holding a bag of peas to his lower jaw and Papyrus plopped down head first into a frozen steak on a plate. Talking hurts, but after numbing the pain Sans takes a look at his brother and tries to spur conversation again.   
   
“...So what was that Boss? Trying to kiss me or something?”  
   
“I shed shawry…” He doesn't look up from the plate he’s sunk his head into, defeated.  
   
“I’m not angry… just…” He sighs, drawing out the long breath through his nasal cavity. Trying to think about how to talk about this. “When I said I wanted to be like the Swap bros I meant, talking and being open. Being _brothers_ again. Boss.” Red pulls the peas from his jaw and wonders if the bleeding has stopped. It was such a sharp clank of teeth, far from a kiss it was more of a headbut. Red nervously spoke again. “You... _always_ hurt me somehow. You make a show to prove to everyone I’m your weak little armrest. And I understand why, it keeps us safe…  but at home, where it matters, we don’t talk. We don’t laugh. Visiting the Swaps is the only time you ever look… _I dont know_ … Its the only time you ever take off your battle gear! I’m sure you sleep in it sometimes _ya know?_ ”  
   
“I do _not_ sleep in it! Thats _filthy_!”  
   
“ _Heh_... “   
   
Some birds tweet along the treetops. An early dawn starts to make the windows glow with the light hues of morning. Paps nurses his chin, the frozen steak now soggy and gross to be fitting over his bones. He sluggishly gets up and takes his plate and the peas back to the freezer. When he turns back, Sans is looking at him. Expectant of something. It fills him with a guilt boiling inside his bones. He wants to get something off his chest.   
   
“When I see those swapped assholes I think… well I get _upset_! Why aren’t _we_ snuggling on the sofa? Why aren’t _we_ making gross pet noises!? We’ve only known the jerks for a couple months and they’re already having their _second_ brat! We’re not even _dating_ Sans!”  
   
Sans bites back the words he wants to say. That it’s wrong for brothers to date. “Well Boss...  you’ve never dated anyone before. You should probably go out and meet other people.”   
   
If he acknowledged that he felt the same way and he felt jealous of the loving connection those Swap brothers had...Red knew he would just be putting them on a pedestal. The Swaps relationship was an impossible goal born from a world of love and peace. If Boss and Red dated… they’d keep striving to have the same thing his alternates had. It would never be the same, they’d always be jealous for more. More hugs. More kisses...  more softness and tenderness that was _impossible_ for them.   
   
“Fuck that nonsense! Who would be more suitable for me than someone who already does what I say. Someone who already cleans and cooks… and doesn't stab me in my sleep?”  
   
“Gosh Boss… what a compliment.” Rolling his eyes he moves to stand from his chair and head to his room.  Papyrus follows, not giving up the conversation as they ascend the stairwell and even blocking Sans door to continue with this crazy talk.   
   
“Fine it’s settled then! You’ll be my wife!”  
   
“Your wha-?” Sans word are caught in his throat as Papyrus picks him up and slings him over his shoulder. “Boss! What the hell are you-!!”   
   
“You’re sleeping in my room from now on!” And like that he drops him onto the bed. “And we’re going to have kids! Lots of em! I’m not letting that smoking bastard get ahead of us!”  
   
“Boss… now you just sound immature.” Red rolled his eyes. “Come one. It’s late. I’m tired. YOU’RE tired. Pfff- this is silly...I’m going back to my room.” He slides from the bed but Papyrus grabs his wrist in his and he pulls him towards him again. This time, jaw clicking, connecting for the chaste of a kiss.   
   
And it's wonderful. It's everything he imagined it would be and Pap holds back from smacking their jaws flat against each other. This kiss was pleasant, and leads to another kiss that Sans can’t deny.   
   
It becomes a heated experience. A tongue pushed into his mouth, probing, nervous. New experience for both of them.  They part, breathless. A red blush dusts both their cheeks as their magic stirs underneath bone. Their eyes connect and there are words that neither need to say outloud to know what the other was begging for.   
   
All protest melted away as frenzied stripping of clothes removes that space between them. Slammed into walls and the back of his skull connects with the hard wall. Another apology, awkwardly shuffling them to the bed. Tripping over clothing and kissing to make up. The night continues through their moans and soft apologies and yearning words to encourage the other not to stop.   
   
Red cries with how good it all feels… and he wonders why he didn’t let this happen sooner. What was he afraid of? Why did he try to push away Boss? This was everything he wanted and more…  
   
But the veil of night lifts eventually. In the morning his spine aches and he rolls out of bed, clacking a skeletal kiss to the top of Paps head. He makes his way to the bathroom and wants to clean up, but instead he’s stuck staring at the odd reflection in the mirror. It’s his own… but with a bloated midsection.   
   
Red starts poking at the gelatinous spawned belly with a finger. The ecto tummy jiggles at his touch, it felt funny that he couldn't dissipate it off his own will. The small glow of light inside it hasn’t taken form yet. There is just the slightest darker shade of red that emits from inside the pouch.    
   
It’s a tiny _souling_.   
   
Red sucks in a breath of air through his gritted teeth. “uh-oh.”   
   
Sans stares at the mirror longer, poking at the small ecto stomach that had formed. He was gonna have a kid. A _fucking_ kid! A half smile played on his lip, he wasn’t quite sure if he should be happy about this or scared.   
   
On one hand this was _good…_ they were having a kid!  
His face glows bright from the lewd things they did last night. Every awkward kiss and apology, helping to prop pillows under his back and asking if something hurt or if he liked it. Boss was so gentle… so concerned for Sans. His brother was patient and loving and it was everything Sans ever wanted. He felt spoiled a bit, letting the bright red glow to his cheeks and he stared at his reflection. Boss _loved_ him… _heheh_..   
   
On the other hand… a monster was growing inside his tummy.   
This was way too quick… he didn’t think that the small fluttering soul would be this big so fast… He didn’t think it would form at all. Boss wanted kids to beat out the Swap bros but … Sans thought it would take a little more time than this. What the hell was he supposed to do?   
   
How… to… baby?  
   
He leaves the bathroom and returns back to the bedroom. He had to tell Boss, but when he opens the door he sees his brother is snoring loudly and sprawled out on the blankets.The skeleton is fast asleep and Red melts at the scene.   
He didn’t want to wake him right now. When was the last time Boss slept in on a weekend? His brother was always the first to wake. After what he did last night, Paps deserved a little more rest. He’d tell him later. Quietly, Red tiptoed to his bedside and snuggled back in under the sheets. The warmth of Boss’s body squeezed him tightly as he hugged him in his sleep. Red closed his eyes and leaned his head against the brothers. He could tell him in the morning… 


End file.
